From c2c5c5cd70f8b311e2e124ca3b5cc1d71c601b7b Mon Sep 17 00:00:00 2001
From: Joona Hoikkala <joohoi@users.noreply.github.com>
Date: Wed, 31 Oct 2018 00:54:51 +0200
Subject: [PATCH] Better error handling in goroutines (#122)
* More robust goroutine error handling using channels
* Fix tests and make startup log msg saner
* Clarification to README and config file
---
.travis.yml | 1 +
README.md | 4 +++-
config.cfg | 4 +++-
main.go | 43 ++++++++++++++++++++++++++++++++++++-------
main_test.go | 13 ++++++++++++-
util.go | 9 ---------
6 files changed, 55 insertions(+), 19 deletions(-)
diff --git a/.travis.yml b/.travis.yml
index 2a63da5..e2211a7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,7 @@
language: go
go:
- 1.9
+ - 1.11
env:
- "PATH=/home/travis/gopath/bin:$PATH"
before_install:
diff --git a/README.md b/README.md
index 5efbfd5..862c190 100644
--- a/README.md
+++ b/README.md
@@ -212,7 +212,9 @@ $ dig @auth.example.org d420c923-bbd7-4056-ab64-c3ca54c9b3cf.auth.example.org
```bash
[general]
-# dns interface
+# DNS interface. Note that systemd-resolved may reserve port 53 on 127.0.0.53
+# In this case acme-dns will error out and you will need to define the listening interface
+# for example: listen = "127.0.0.1:53"
listen = ":53"
# protocol, "udp", "udp4", "udp6" or "tcp", "tcp4", "tcp6"
protocol = "udp"
diff --git a/config.cfg b/config.cfg
index 531c964..d93d3fb 100644
--- a/config.cfg
+++ b/config.cfg
@@ -1,5 +1,7 @@
[general]
-# dns interface
+# DNS interface. Note that systemd-resolved may reserve port 53 on 127.0.0.53
+# In this case acme-dns will error out and you will need to define the listening interface
+# for example: listen = "127.0.0.1:53"
listen = ":53"
# protocol, "udp", "udp4", "udp6" or "tcp", "tcp4", "tcp6"
protocol = "udp"
diff --git a/main.go b/main.go
index 67b6cd8..063f7b2 100644
--- a/main.go
+++ b/main.go
@@ -11,6 +11,7 @@ import (
"syscall"
"github.com/julienschmidt/httprouter"
+ "github.com/miekg/dns"
"github.com/rs/cors"
log "github.com/sirupsen/logrus"
"golang.org/x/crypto/acme/autocert"
@@ -55,16 +56,41 @@ func main() {
DB = newDB
defer DB.Close()
+ // Error channel for servers
+ errChan := make(chan error, 1)
+
// DNS server
- startDNS(Config.General.Listen, Config.General.Proto)
+ dnsServer := setupDNSServer()
+ go startDNS(dnsServer, errChan)
// HTTP API
- startHTTPAPI()
+ go startHTTPAPI(errChan)
+ // block waiting for error
+ select {
+ case err = <-errChan:
+ if err != nil {
+ log.Fatal(err)
+ }
+ }
log.Debugf("Shutting down...")
}
-func startHTTPAPI() {
+func startDNS(server *dns.Server, errChan chan error) {
+ // DNS server part
+ dns.HandleFunc(".", handleRequest)
+ log.WithFields(log.Fields{"addr": Config.General.Listen}).Info("Listening DNS")
+ err := server.ListenAndServe()
+ if err != nil {
+ errChan <- err
+ }
+}
+
+func setupDNSServer() *dns.Server {
+ return &dns.Server{Addr: Config.General.Listen, Net: Config.General.Proto}
+}
+
+func startHTTPAPI(errChan chan error) {
// Setup http logger
logger := log.New()
logwriter := logger.Writer()
@@ -90,7 +116,7 @@ func startHTTPAPI() {
cfg := &tls.Config{
MinVersion: tls.VersionTLS12,
}
-
+ var err error
switch Config.API.TLS {
case "letsencrypt":
m := autocert.Manager{
@@ -109,7 +135,7 @@ func startHTTPAPI() {
ErrorLog: stdlog.New(logwriter, "", 0),
}
log.WithFields(log.Fields{"host": host, "domain": Config.API.Domain}).Info("Listening HTTPS, using certificate from autocert")
- log.Fatal(srv.ListenAndServeTLS("", ""))
+ err = srv.ListenAndServeTLS("", "")
case "cert":
srv := &http.Server{
Addr: host,
@@ -118,9 +144,12 @@ func startHTTPAPI() {
ErrorLog: stdlog.New(logwriter, "", 0),
}
log.WithFields(log.Fields{"host": host}).Info("Listening HTTPS")
- log.Fatal(srv.ListenAndServeTLS(Config.API.TLSCertFullchain, Config.API.TLSCertPrivkey))
+ err = srv.ListenAndServeTLS(Config.API.TLSCertFullchain, Config.API.TLSCertPrivkey)
default:
log.WithFields(log.Fields{"host": host}).Info("Listening HTTP")
- log.Fatal(http.ListenAndServe(host, c.Handler(api)))
+ err = http.ListenAndServe(host, c.Handler(api))
+ }
+ if err != nil {
+ errChan <- err
}
}
diff --git a/main_test.go b/main_test.go
index 54348db..23771ad 100644
--- a/main_test.go
+++ b/main_test.go
@@ -7,6 +7,7 @@ import (
logrustest "github.com/sirupsen/logrus/hooks/test"
"io/ioutil"
"os"
+ "sync"
"testing"
)
@@ -42,7 +43,15 @@ func TestMain(m *testing.M) {
_ = newDb.Init("sqlite3", ":memory:")
}
DB = newDb
- server := startDNS("0.0.0.0:15353", "udp")
+ server := setupDNSServer()
+ // Make sure that we're not creating a race condition in tests
+ var wg sync.WaitGroup
+ wg.Add(1)
+ server.NotifyStartedFunc = func() {
+ wg.Done()
+ }
+ go startDNS(server, make(chan error, 1))
+ wg.Wait()
exitval := m.Run()
server.Shutdown()
DB.Close()
@@ -57,6 +66,8 @@ func setupConfig() {
var generalcfg = general{
Domain: "auth.example.org",
+ Listen: "127.0.0.1:15353",
+ Proto: "udp",
Nsname: "ns1.auth.example.org",
Nsadmin: "admin.example.org",
StaticRecords: records,
diff --git a/util.go b/util.go
index 695c6c4..c835a0d 100644
--- a/util.go
+++ b/util.go
@@ -10,7 +10,6 @@ import (
"strings"
"github.com/BurntSushi/toml"
- "github.com/miekg/dns"
log "github.com/sirupsen/logrus"
)
@@ -108,14 +107,6 @@ func setupLogging(format string, level string) {
// TODO: file logging
}
-func startDNS(listen string, proto string) *dns.Server {
- // DNS server part
- dns.HandleFunc(".", handleRequest)
- server := &dns.Server{Addr: listen, Net: proto}
- go server.ListenAndServe()
- return server
-}
-
func getIPListFromHeader(header string) []string {
iplist := []string{}
for _, v := range strings.Split(header, ",") {
--
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